I think one thing that I have been learning is UI is all about user expectation and meeting that. In a good design, things are just where they should be, the majority of users expect them to be in the same area and gravitate towards that… I find that really interesting.

The other thing I have noticed is that bad UI makes people feel dumb. If the system is too complicated, users feel stupid because they can’t figure it out. I think that is why Apple users love their products so much. They feel empowered (or liberated if they switched over from the Windows world). The UI just gets out the way and lets you do what you need to do. You feel smart when you use it because you can be so efficient and your expectations are met.